1. Field of the Invention
The present invention pertains generally to an article of manufacture which facilitates the application and sealing of sheet-like membranes, such as rubberized roofing materials, to the outside edges of buildings; more particularly, to a sheet metal mini-wall parapet which replaces prior art parapets which are labor intensive to make and install, and are not as sturdy and long lasting as our invention. The mini-wall parapet of this invention also allows it to be fully prefabricated in the shop of sheet metal, such as galvanized steel, aluminum, stainless steel, or other corrosion resistant metal, without the use of any wood or masonry in the structure.
2. Discussion of the Background of the Invention
Roof edge sealing constructions are referred to in the literature by several names such as mini-wall parapets, coping structures, roof edge assemblies, gravel stop assemblies, water dams, and the like. These devices are provided for the purpose of sealing the outer edges of roof construction components by anchoring the sheet-like roofing membranes to the roof edges. They also serve to retain ballasts, control water drainage, or for supporting fascia members at the interfaces between various constructions and structures. For purposes of this disclosure, we will refer to these devices as mini-wall parapets. In the description of the drawings which follows, all elements in common with prior art FIGS. 1A and 1B, will include the same numbering system insofar as possible. Also, the dimensions of the various elements are not true to scale, and certain portions of the drawings may be depicted as exaggerated in thickness or thinness to facilitate their disclosure.
As indicated by prior art FIG. 1A, edge sealing mini-wall parapet 1, is fabricated on the site at the edge of the roof deck 2 by layering a plurality of wood planks 3 (such as 2×6's or 2×8's), as shown at interface 17. Such a mini-wall parapet 1 is typically formed from so-called pressure treated wood so that it is assured of moisture and insect resistance, but untreated wood can be utilized as well, provided that the wood is well-sealed from moisture and insects by the rest of the structure. If the deck 2 is of concrete or masonry construction, the lowermost wood plank 3 is secured to roof deck 2 by anchor bolts or masonry fasteners 4. If the deck 2 is of wood or metal construction, the lower layer 3 is screwed to the deck. In that case, the fastening elements 4 are screws. Each of the subsequent wood layers 3 are securely nailed to the next lower layer by nails 5. The number of layered planks 3 required is determined by the thickness of the insulation layer 6, whereby the mini-parapet is at least a minimum height above the insulation layer 6.
At the outside top of the typical wood mini-parapet 1, there is provided a triangular element 8 with the hypotenuse of the triangular shape facing the inside of the mini-parapet. Member 8 is also of pressure treated wood, and is nailed (toenail fashion) to the upper wood layer 3 by nails 9. The triangle shaped member 8 is provided as a gravel stop where a gravel ballast is used, and/or to deflect water back toward the roof so that it does not drip excessively over the outside wall of the building.
The roof deck 2 is shown over a conventional outside wall 18, which may be of brick or block or a combination thereof. The roof deck 2 is attached to the outside wall 18 at interface 19 in the conventional manner.
The roof membrane 7 is glued or otherwise installed over the roof insulation layer 6, and continues to lap over the mini-wall parapet 1, over the gravel stop 8, and partially down the outside of the mini-wall parapet as shown. An elongated cleat 11 of corrosion resistant sheet metal is either nailed or screwed by elements 12 laterally along the length of the mini-wall parapet into the lower wood layer 3. The elements 12 can also be masonry attachments if the elongated cleat 11 is installed laterally along the length of concrete roof deck 2 into the outside edge of roof deck 2. See prior art FIG. 1B, and FIG. 2B.
The bottom of the cleat 11 is bent outward slightly as shown at 13, so that a finishing cap or coping member 10 can be resiliently installed. The coping member 10 is also of corrosion resistant sheet metal and includes an inverted flange 16 which snuggly engages the outwardly bent bottom edge 13 of the cleat 11 when installed. The coping member 10 is prefabricated by bending its sheet metal in the shape shown. The coping member 10 and the cleat 16 are sufficiently flexible, as indicated by dotted portion 9, so that they can be elastically deformed when the coping member 10 is snapped over the top of member 8 and the roof membrane 7 when final installation is made. The upper end of the coping member 10 is downwardly bent at 14 so that the upper end fits snuggly over the element 8 and the roof membrane 7. The coping member 10 may have an outwardly bent lip 15. This lip minimizes the possibility that the coping member 10 might snag or even cut the roof membrane 7 when the coping member is installed. The lip 15 also minimizes injury to the installer when the coping member 10 is installed. As noted above, the coping member 10 and the cleat member 11 are sufficiently flexible so that they can be elastically deformed (see dotted depiction at 9) when the coping member 10 is installed over the top of the mini-wall parapet, without exceeding the elastic limit of any of the bends in the coping member 10 or of the cleat 11. Thus when installed, the coping member 10 snaps snugly and permanently over the elements of the mini-wall parapet 1 and the sealed edge of the roof membrane 7. Therefore, the mini-wall parapet 1 is fully protected from weather and moisture. In all of these embodiments, elements are shown with exaggerated spacing between the elements for clarity of disclosure. In actual structure, such spacing would be minimized.
Prior art FIG. 1B discloses a sheet metal variation of the mini-wall parapet 1. The wood planks 3 of FIG. 1A have been eliminated and replaced by the one-piece, generally U-shaped sheet metal structure 3. U-shaped sheet metal structure 3 can be prefabricated in the shop prior to installation at the site. The gage of the generally U-shaped structure 3 is chosen to have sufficient vertical strength to easily function as a mini-wall parapet. At the first step in its installation, the U-shaped member is still open at the top, whereby the structure can be easily attached along the roof edge at 17. As shown in FIG. 1B, the bottom wall member 22 is attached to the roof deck 2 by screws or masonry anchors 4, depending on the composition of deck 2. The lower left hand corner of the U-shaped member 3 is folded over on itself to form a double layer, and the double layer extends generally downwardly to form the cleat 11, Cleat 11 functions in the same manner as the cleat of prior art FIG. 1A. The cleat 11 is bent slightly outwardly at its lower edge as shown by element 13 in the same manner as in prior art FIG. 1A. If deemed necessary, cleat 11 can be further adhered to the edge of the roof deck 2 by the lateral fasteners 12.
At the top, opposite ends of the U-shaped element 3 are two staggered end elements 20 which are folded over as shown. The two folded over elements 20 are staggered vertically in height and sloped to receive the top member 8. The slope allows for the drainage of water toward the roof. Thus, when the top member 8 is installed, it performs the same general function as element 8 performs in prior art FIG. 1A. Top member 8 is attached to the U-shaped elements by screws 5. The top member 8 is of pressure treated plywood, and, although it can be prefabricated in the shop, it should be installed in the field to allow access to the interior of the U-shaped element 3 when it is fastened to the roof deck 2. The top member 8 can also be horizontal if desired, but such a configuration would not positively cause drainage toward the roof. The top member 8 can also be prefabricated of sheet metal, but plywood is preferred. Once the top member is installed, it provides even greater rigidity to the mini-wall parapet assembly. Further, the inner cavity of the mini-wall parapet 1 of prior art FIG. 1B can be filled with fiber glass, foam, mineral wool, or other insulation 27 to provide further thermal insulation if that is deemed necessary.
Thereafter, the membrane 7 and the coping member 10 are installed in the same manner as in FIG. 1A. The coping member 10, although of different shape from that used in FIG. 1A, is installed and functions in the same manner as coping member 10 in prior art FIG. 1A. The outward appearance of the mini-wall parapet of FIG. 1B from the ground, from an aesthetic standpoint, is virtually identical to that of FIG. 1A.